• Estimated Use of Plant Nutrients in Arizona, by Crops

      Pawson, W. W.; Stanberry, C. O.; Fuller, W. H.; Tucker, T. C.; Pew, W. D.; Hillman, J. S. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
    • Fertilizer Placement in Potato Production

      Pew, W. D.; Park, J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      The importance of proper fertilizer placement has been demonstrated in recent greenhouse studies. Small, seemingly unimportant changes in fertilizer placement often in reality are very important. Specially constructed boxes with glass fronts were used to study root development as affected by fertilizer placement. Yields were significantly different one from another with the poorer ones resulting where fertilizers were placed too close to the seed piece. Yields ranging from 298 cwt, where the fertilizer was placed two inches to each side and level with the seed piece; up to 367 cwt where the fertilizer was placed four inches to each side and two inches below the seed piece. Root burning and speed of root regeneration represent the most important consideration to be reckoned within the proper placement of fertilizer.
    • Fertilizer Studies with Potatoes in the Queen Creek Area

      Turner, Fred Jr.; Pew, W. D. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      In a fertilizer study in the Queen Creek area, a strong response to nitrogen and phosphorus fertilizers was obtained. Potatoes did not respond to potassium when applied with nitrogen and phosphorus.
    • Influence of Seed Piece Size on Potato Yields

      Pew, W. D.; Park, J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      During the past several years considerable experimenting has been aimed at developing methods for improving potato yields. One of the easiest and most effective ways found was to adjust the seed piece size and number of eyes per piece. Seed pieces were cut to meet the following size categories: 1/2, 1, 1-1/2, and 2 ounces and small whole tubers; 1-1/2, 2 and 2-3 ounces. Significant differences in yield were obtained between the various seed piece size treatments. The yield advantage was in favor of the larger size. The number of eyes per piece was less important except with the smallest size. In this case the seed pieces were incapable of adequately supplying plant growth from more than one eye. Small, whole tubers from good high yielding fields were found to be excellent for seed potato pieces.
    • Irrigation Practices with Potatoes

      Pew, W. D.; Park, J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Data from five years of experimentation with irrigation and soil moisture levels indicate that a certain knowledge and general understanding of these factors is important in potato production. Nine treatments ranging from a constant very wet level to a constant dry treatment were used. Yield differences were significant and varied from a low of 321 cwt, from plants exposed to a very wet (18-20 centibars tension) level early in the season followed by a dry (75-80 centibars tension) condition during the last part of the growing season, to 416 cwt where the plants were kept at a dry level early and changed to a very wet level late in the season. Growers often unknowingly reduce yields and lower quality by applying excessive amounts of irrigation water.
    • Irrigation Studies with Carrots

      Pew, W. D.; Park, J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Data from four years of irrigation studies with carrots indicate this crop has a rather wide tolerance to varying soil moisture levels as measured by yield and quality of roots. Yields have varied between treatments from 514 to 665 crates per acre. Soil moisture levels ranging from a very wet level (18-20 centibars of tension) to a dry level (75-80 centibars of tension) have shown no significant differences in yield. Only from treatment 5, the very dry schedule, was the yield significantly lower than for all other treatments.
    • Irrigation Trials with Cabbage

      Pew, W. D.; Park, J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      The influences of soil moisture are pronounced in cabbage grown under Arizona's semiarid conditions. An understanding of these effects is a must if the most effective cabbage production is to be achieved. High, constant levels of moisture reduces solidity, increases apparent size, reduces color and general market acceptance. On the other hand, dry soil moisture conditions increases solidity and color and reduces size and generally impairs market quality because of the smallness of size and the tough and woody texture of the cabbage thus produced. Best quality cabbage commensurate with acceptable yields and greatest effectiveness is obtained where moisture is kept at 75-80 centibars of tension.
    • Potato Fertilization

      Pew, W. D.; Park, J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Results from experiments with varying levels of nitrogen, phosphorus and potassium have shown that the ratios of 1 - 2.5 - 0 to 1 - 3 - 0 produce the highest yields. While the ratio between nitrogen and phosphorus appears important, the water solubility of the phosphorus seems to be the most important factor in proper fertilization. Proper placement of the fertilizer as well as irrigation and other cultural practices are musts in potato production.
    • Response of Dry Onions to Varying Levels of Soil Moisture

      Pew, W. D. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Onions respond favorably to increasing levels of soil moisture as measured by increase in bulb size and total yields. Maintaining a soil moisture level of 18-20 centibars of tension (nearly field-holding capacity) produces the greatest yields of bulbs. However, dry onions so produced are somewhat softer in texture, tended toward thick -neck growth, matured slower, and are more difficult to cure adequately in the normal length of time. Onions grown on lesser amounts of water tend to have the reverse characteristics. Costs of production are similarly increased under high soil moisture levels because of the need for replacing nitrogen leached out of the root zone. Also, the costs of the water and its application must be increased. Therefore, the economics involved would be a required consideration.